Collaborative Research:RUI:P2C2: Extending Key Records of Holocene Climate Change and Glacier Fluctuations in the North Pacific Region Using Subfossil Wood from Southeastern Alaska

该项目的目的是开发一个多千年，树木年轮年表从阿拉斯加东南部冰川退缩暴露的亚化石树木到精确的全新世冰川波动，并将其与气候季节性的新记录进行比较。多千年的树木年轮年表将被用于扩展春季和夏季温度的重建，并通过分析每年树木年轮中的创伤树脂管来建立冬季风暴的新记录。冬季风暴重建与阿留申低压系统（AL）的强度有关，其分析有可能改变对北太平洋冷季海洋-大气变率的理解。该项目的具体目标是：1）生成2,000年的冬季AL沿着夏季温度变化的记录，以确定它们如何响应过去的气候强迫。2)使用树木年代学来精确地确定在过去的4000年中，七个陆地终止冰川和两个冰川的前进和后退时间。3)测试阿拉斯加南部沿海最广泛的全新世冰川进展发生在夏季气温较低（融化减少）与增强的AL（降雪增加）相吻合的假设。潜在的更广泛影响包括收集对时间敏感的埋藏木材档案，供科学界进行多学科调查。该项目将对春夏气温、冬季风暴和冰川进退进行新的重建，以更好地了解气候-冰川物质平衡的动态和北太平洋千年时间尺度的十年变化。该项目将为四名本科生提供培训，作为其本科论文的一部分，包括实地考察，数据分析和结果展示。研究人员将通过在冰川湾国家公园举行两次演讲来参与公众宣传。此外，本发明还提供了一种方法，与Hoonah印第安人协会和Hoonah土著森林伙伴关系合作的树木年代学研讨会将在Hoonah的阿拉斯加土著村组织，目的是让学生参与以收集和分析树木为中心的技能型技术，该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准。

This project aims to develop a multi-millennial, tree-ring chronology from subfossil trees exposed by retreating glaciers in Southeast Alaska to precisely calendar-date Holocene glacier fluctuations and compare them with a new record of climate seasonality. The multi-millennial tree-ring chronology will be used to extend reconstructions of spring and summer temperatures and build new records of winter storminess by analyzing traumatic resin ducts in annual tree rings. The winter storminess reconstruction is related to the strength of the Aleutian Low-pressure system (AL) and its analysis has the potential to transform the understanding of cold season ocean-atmospheric variability in the North Pacific. Specific goals of this project are to: 1) Generate 2,000-year-long records of wintertime AL along with summer temperature variability to determine how they responded to past climate forcing. 2) Use dendrochronology to precisely date when seven land-terminating and two tidewater glaciers advanced and retreated during the last 4000. 3) Test the hypothesis that the most extensive Holocene glacier advances in south coastal Alaska occurred when cooler summer air temperatures (reduced melt) coincided with a strengthened AL (increased snowfall). The potential Broader Impacts include the collection of time-sensitive archives of buried wood that would be available to the scientific communities for multi-disciplinary investigations. The project will generate new reconstructions of spring-summer temperature, winter storminess and glacier advance/retreats to better understand the dynamics of climate-glacier mass balance and the North Pacific decadal variability at millennial time scales. This project will provide training for four undergraduate students as part of their undergraduate thesis including field work, data analysis and presentation of the results. The researchers will engage in public outreach by giving two talks at Glacier Bay National Park. In addition, a dendrochronology workshop in partnership with the Hoonah Indian Association and the Hoonah Native Forest Partnership will be organized in the Native Alaskan Village of Hoonah with the goal of engaging students in skill-based technique centered on the collection and analysis of tree-ring records.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.